Techniques have been developed and widely used for remote control of devices installed in automobiles (hereinafter, also referred to as “vehicles”). For example, techniques have been developed for starting engines of vehicles by remote control to preliminarily warm-up the engines, and for activating air conditions of vehicles by remote control to control a temperature in the vehicles after starting the engines before passengers enter the vehicles. Such techniques are disclosed in Japanese Laid-open Patent Publication No. 11-230013 (patent document 1).
Patent document 1 describes a technique involving a control circuit for control of an aftermarket electric device installed in a vehicle. This vehicle has an engine control circuit that is wirelessly controllable to start/stop the engine of the vehicle through operation of a portable controller (remote controller) provided with a start switch and a stop switch. The aftermarket electric device is turned on by an operation-start signal which is an operation signal from the start switch during operation of the engine and turned off by an operation-stop signal which is an operation signal from the stop switch during a halt of the engine.
In addition to the preliminary air-conditioning described above, the inventors have believed that electric vehicles and plug-in hybrid vehicles that are chargeable via household wall sockets can be more convenient with remote detection and control of the start and stop of the electrical charge of the vehicles in a chargeable state in which the charging systems of the vehicles are connected to electric sockets. Such remote control of various devices enhances the convenience of the vehicles in use.
Dedicated portable controllers provided for the respective devices to be remotely controlled lead to increased costs, management burden, and incorrect operation. Such drawbacks are solved by the technique disclosed in patent document 1, which enables devices to be remotely controlled by a portable controller.
This technique uses a switch operation logic of a single switch to remotely control multiple devices. Consequently, an increase in the number of devices to be remotely controlled causes an increase in the complexity of the switch operation logic. Such a complicated switch operation logic cannot be readily operated and may lead to incorrect operation. The portable controller may be equipped with switches corresponding to the devices to be remotely controlled. In such a case, however, the switch configuration of the portable controller becomes complicated, and makes operation difficult that incorrect operation would increase.
The inventors have conceived the use of mobile communication devices, such as mobile phones, for remote control of various devices in a vehicle. The mobile phones popular today are multifunctional mobile phones, which are referred to as “smartphones.” Smartphones have functions similar to those of personal computers and personal digital assistants (PDAs), and typically are equipped with touch panel displays. Thus, application software can be downloaded to obtain desired functions, allowing smartphones to remotely control in-vehicle devices.
That is, the application software can be developed to display a menu and switch buttons on a touch panel display for remote control of devices and to operate the switch buttons. The application software can be downloaded to a smartphone, enabling the smartphone to be used as a remote controller of the devices. The flexibility in the menu display facilitates appropriate operations without incorrect operation.
Wireless communication between a mobile communication device, such as a smartphone, and a vehicle requires the vehicle to be equipped with a wireless communication device (communication control device) supporting the communication standard (network interface) employed by the mobile communication device. The communication standards of smartphones include Wi-Fi (trademark) and 3G. In addition to these, communication standards, such as WiMAX (trademark) and Bluetooth (trademark) may also be used.
Among these communication standards, Wi-Fi has a relatively high communication rate, a relatively large wireless communication distance, and a low running cost due to its high versatility that does not require a communication infrastructure. Thus, mobile communication devices that support Wi-Fi can be readily used for remote control of in-vehicle devices. In such a case, a wireless communication device supporting such a standard is installed in the vehicle. Generally, such a wireless communication device in the vehicle is always in a communication standby mode and is ready to receive transmission from a smartphone or any other devices at all times.
Unfortunately, the wireless communication device in the vehicle that is in a communication standby mode constantly discharges its battery, which is the power source of the wireless communication device, due to a standby current. As a result, the state of charge of the battery rapidly decreases. In other words, upon performing a wireless communication between mobile communication devices that support Wi-Fi and the vehicle, the constant standby mode of the wireless communication device is advantageous as above, whereas this standby state requires a large standby current and causes a rapid decrease the state of charge of the battery. Especially, the state of charge of a battery having a small capacity tends to drop significantly due to the consumption by the standby current. This is a major problem.
Electric vehicles and plug-in hybrid vehicles have large-capacity high-voltage sources (batteries for running the vehicles). A candidate method of charging the battery as the power source of the wireless communication device is periodic supply of electric power from the high-voltage source. This way, the electric power consumed by the wireless communication device for the stand-by current can be supplemented to constantly maintain the communication stand-by mode of the wireless communication device.
An important issue for electric vehicles and plug-in hybrid vehicles is an improvement in the cruising distance in motor traveling. Although the batteries are chargeable with high-voltage sources, there is a strong demand for saving the power charged in the high-voltage sources. A scheduled charge of a battery in a low-temperature environment may result in an insufficient charge capacity of the battery because the charge acceptance of the battery is lower than that in a normal-temperature environment. If the wireless communication device is constantly in a communication stand-by mode, the charge capacity of the battery runs short and the battery runs out.